The Dirty Girls require gluing on a velcro tab to work properly and the levagaiters do not. So the price difference between something that requires you to permanently alter your shoes and to buy new velcro with every shoe replacement vs a single piece of gear that works by itself is warranted.

Now in practice is one better than the other, not really just depends on what you prefer.

I liked the design and fit of Dirty Girls, but the stitching on mine started to unravel within the first 100 miles of use (all of which was on well-maintained trails). I ended up going over all of the stitching with a sewing machine before my PCT thru-hike. Even then, the hook came off of one pair 2/3 of the way through the trail. YMMV.

If you use a silicone based product and locate the velcro on a portion of the heel of the shoe that is part of the sole, the velcro and the adhesive can be peeled off. I found this to be true after hiking through some rockier portions of the AT last October. I visited the local outfitter and was gifted with enough seam seal to reattach the velcro to the heel of my shoe. I finished the last 50 miles of our hike without further incident.